Rate-matching is a technique widely used in 3G wireless communication systems, such as UMTS and CDMA2000, for adjusting the data size of the channel encoder outputs at the transmitter to the air interface capacity. Rate-matching applies puncturing or repetition to each channel's data based on well-known calculated rate-matching parameters. Within a channel, a puncture or repetition pattern is applied. A reverse process called rate de-matching is performed by the receiver side to restore the punctured/repeated data.
The conventional implementation of rate-matching and rate de-matching is to use software to do both parameter calculation and data processing (i.e., puncture and repetition as dictated by the parameter calculation). As used herein, software refers to instructions stored in memory, that when executed cause a general purpose processor, computer or controller to perform a particular function. Using software refers to the general purpose processor, computer or controller executing the instructions and thus performing the particular function specified by the software.
Unfortunately, a general purpose processor running software to perform rate-matching (e.g., a programmed digital signal processor (DSP)) requires in the order of 60 instruction cycles per bit of processed data to perform the puncturing and repetition process. The processor load required for processing 64 users is in the order of 240 million cycles per second which is an excessive load. The majority of the DSP's processing power is consumed with the puncturing/repetition processes, which are very simple iterative bit operations.